Apparatus for creation of a falling curtain of liquid



APPARATUS FOR CREATION OF A FALLING CURTAIN OF LIQUID Filed Feb. 13, 1964 2 Sheets-Sheet l 1 INVENTORS 18 SE, \o? STEPHEN J. FRAEMKEL, 8i 56 FREDERICK u ADAMS,

8O 2 E3 7 JAMES G. BUCK 2:

PHILIP F CATALANO W, m, MW

Jan. 23, 1968 5, J. FRAENKEL ETAL 3,355,325

APPARATUS FOR CREATION OF A FALLING CURTAIN OF LIQUID 2 Sheets-Sheet Filed Feb. 13, 1964 INVENTORS STEPHEN J.FIZAEMKEL,

- FIZEDEIZICK w. Aonns.

' JRMES G. Bucn; PHIUP F cmmuo MP5 ATTORNEYS United States Patent 3,365,325 APPARATUS FOR CREATION OF A FALLING CURTAIN OF LIQUID Stephen J. Fraenkel, Winnetka, Frederick W. Adams, Clarendon Hills, James G. Buck, Western Springs, and Philip F. Catalano, Chicago, Ill., assignors to Continental Can Company, Inc., New York, N.Y., a corporation of New York Filed Feb. 13, 1964, Ser. No. 344,600 24 Claims. (Cl. 117105.3)

ABSTRACT OF THE DISCLOSURE This invention is directed to an apparatus for creating a uniformly thin curtain of falling liquid comprising a substantially elongated porous member having converging side surfaces terminating at an elongated terminal edge which may be pervious or impervious. Means are provided for delivering liquid either to and through said member or liquid along the converging side surfaces during the flow of gas to and through the porous member for in each case creating a thin curtain of the liquid as it departs from the thin edge. The elongated member may be of a linear construction for coating planar web material or may be circular for coating tubular stock. In keeping with another aspect of the invention a pair of elongated members which are not necessarily porous define a gap therebetween and expandable means are provided for adjusting the gap by being energized from a source of electrical potential to vary the thickness of the curtain issuing from the gap.

One particular use of the novel apparatus of this invention, for example, is to create a continual uniform falling curtain of liquid coolant for treating wax coated web material.

At present, it is conventional to support a weir-like structure above and transverse to a wax-coated sheet or web of material. Such conventional weir-like structures usually include an overflow Weir which directs a cooling medium, such as water, to a delivery chute. The delivery chute delivers the overflow of the cooling medium in a sheet or stream upon the wax coated web or sheet of material as the material is conveyed beneath and beyond the weir-like structure.

The sheets or streams of coolant issuing from these conventional weir-like structures are generally diflicult to control, and are susceptible to parting along the distance spanned by the streams, particularly at low rates of flow. A further disadvantage of such conventional weir-like structures is the relatively complicated and expensive construction of the structures.

It is, therefore, an object of this invention to provide novel apparatus for creating a planar curtain of falling liquid which is uniform with respect to the distance traversed by the apparatus, and the speed at which web is conveyed beneath and beyond the apparatus.

It is a further object of this invention to provide novel apparatus for creating a tubular curtain of falling liquid for uniformly coating an external surface portion of a continuous tubular member as the member is conveyed through the apparatus at a relatively constant speed.

A further object of this invention is to provide novel apparatus for creating a uniformly thin curtain of falling liquid which eliminates the need for complicated and expensive components, and is relatively simple in both construction and operation.

Still another object of this invention is to provide novel apparatus for creating a uniformly thin curtain of falling liquid comprising a substantially elongated porous memher having a substantially elongated edge portion, and

Patented Jan. 23, 1968 ICC means for delivering liquid toward the edge portion for creating a relatively thin and uniform falling curtain of liquid.

A further object of this invention is to provide novel apparatus for creating a uniformly thin tubular curtain of falling liquid comprising a substantially circular porous member defining an opening and terminating in a generally circular edge portion, and means for delivering liquid toward the edge portion for creating a relatively thin and uniform tubular curtain of liquid.

Another object of this invention is the provision of novel apparatus for creating a uniformly thin curtain of liquid including a substantially elongated porous member, the member having surfaces converging toward an elongated edge portion and a trough for directing liquid to and through the porous member.

Another object of this invention is to provide novel apparatus of the type immediately above-described in which the converging surfaces are each outwardly concavely curved or inwardly convexly curved adjacent the elongated edge portion of the porous member.

Another object of this invention is to provide a novel apparatus of the type above-described in which the elongated edge portion terminates in a relatively sharp, impervious elongated edge.

A further object of this invention is to provide novel apparatus for creating a uniformly thin curtain of falling liquid including porous means, the porous means terminating in an elongated edge whereby liquid urged through the porous means issues from the elongated edge in a relatively thin and uniform falling curtain of liquid, and means for preventing contraction of the liquid curtain along the length thereof, the contraction preventing means including at least two members spaced along and projecting substantially beyond the elongated edge.

A further object of this invention is to provide novel apparatus for creating a uniformly thin curtain of falling liquid comprising first and second porous means of different porosities, one of the porous means including a substantially elongated porous member having an elongated edge, a liquid manifold in fluid communication with the first porous means and a gas manifold in fluid communication with the second porous means.

Still another object of this invention is to provide novel apparatus for creating a uniformly thin curtain of falling liquid comprising first and second elongated members defining therebetween an elongated gap and a conductive element seated in the gap whereby the gap can be adjusted in size by energizing the conductive element through a source of electric potential.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawing.

In the drawing:

FIGURE 1 is a top perspective view of a novel apparatus constructed in accordance with this invention, and illustrates a generally elongated porous member supported above and transverse to a moving web of material having a Wax coated surface, a curtain of liquid falling from the elongated member and means for preventing contraction of the falling curtain along the length of the porous member.

FIGURE 2 is an enlarged transverse sectional view taken along line 22 of FIGURE 1, and more clearly illustrates the porous member, a trough formed in the porous member and a manifold for directing liquid to the porous member.

FIGURE 3 is a fragmentary top schematic view, and illustrates a plurality of the porous members joined in endto-end relationship, and a manifold for directing liquid to each of the individual porous members.

FIGURE 4 is a transverse sectional view of another apparatus for creating a falling curtain of liquid similar to the apparatus of FIGURE 2, and illustrates a porous member having converging surfaces which are each outwardly concavely curved adjacent a lowermost edge of the porous member.

FIGURE 5 is a transverse sectional view similar t FIGURE 4, and illustrates another porous member having converging surfaces which are each inwardly convexly curved adjacent a lower impervious edge of the member.

FIGURE 6 is a fragmentary perspective end view of another apparatus for creating a uniform curtain of falling liquid, and illustrates a pair of converging members defining an elongated gap therebetween and an electrically conductive element seated in the elongated gap.

FIGURE 7 is an enlarged fragmentary transverse sectional view taken through the apparatus of FIGURE 6, and more clearly illustrates the conductive element seated in the elongated gap between the converging members.

FIGURE 8 is a transverse sectional view of an apparatus similar to the apparatus illustrated in FIGURE 4, of the drawing, and illustrates a manifold for directing a gaseous medium into a trough of a porous member, and a gate member at either side of the pervious member for directing a liquid medium against exposed wall surfaces of the porous member.

FIGURE 9 is a transverse sectional view of another apparatus for creating a uniformly thin curtain of falling liquid, and illustrates two porous elongated members of different porosities and a manifold in communication with each of the two porous members.

FIGURE 10 is a transverse sectional view of another apparatus for creating a curtain of falling liquid, and illustrates a porous elongated member and a pair of manifolds both in fiuid communication with the porous member.

FIGURE 11 is a transverse sectional view of another apparatus similar to the apparatus of FIGURES 9 and 10, and illustrates porous members of different porosities and a manifold in fluid communication with each of the members.

FIGURE 12 is a top perspective view of another apparatus of this invention, and illustrates a generally circular porous member terminating in a downwardly directed edge, a continuous tube being conveyed downwardly through the member and a falling tubular curtain of liquid being applied to the exterior surface of the tube.

FIGURE 13 is an enlarged transverse sectional view taken along line 13-13 of FIGURE 12, and more clearly illustrates the tubular curtain of liquid being applied to the exterior surface of the tube.

FIGURE 14 is a top perspective view of another apparatus, and illustrates a generally elongated porous member supported above and transverse to a moving web of material and a curtain of coating liquid falling from the porous member and coating the moving web.

An apparatus constructed in accordance with this invention for creating a uniformly thin curtain of falling liquid is best illustrated in FIGURES l and 2 of the drawing, and is generally designated by the reference numeral 10. The apparatus 10 comprises a substantially elongated porous member 11 of a substantially triangular cross-seetional configuration (FIGURE 2) having a top wall or surface 12 and two downwardly, converging walls or surfaces 13, 14. The porous member 11 is illustratively constructed from porous carbon but may, for example, also be constructed from porous ceramic, porous plastic or sintered metal. A trough 15 opens upwardly through the surface 12 of the porous member 11, and extends substantially the entire length of the porous member 11 but terminates short of the ends thereof.

A liquid manifold 16 is bonded or otherwise conventionally secured to the upper surface 12 of the porous member 11. A seal or gasket 17 can be seated between the upper surface 12 0f the porous member 11 and a lowermost surface 18 of the manifold 16 to prevent the leakage of liquid in a known manner. A conduit 20 is secured in a threaded opening 21 (FIGURE 2) of an elongated bar or plate 22 of the manifold 16. The conduit 20 is placed in liquid communication with a source of pressurized fluid coolant such as water, by, for example, connecting the conduit 26 to a conventional water main.

The apparatus 10 is supported transverse to and above a sheet or web of material S having an upper wax coated surface W. The sheet S is preferably constructed from paperstock material, but may be of any type material which has a wax coating which is to be made glossy by administering a sudden chill to the wax. Such wax coated sheet S is conveyed in a conventional manner toward and beneath the apparatus 10. The wax W is applied to the sheet S just prior to the approach of the sheet material directly beneath a relatively sharp, elongated edge 23 of the porous member 11.

Water is admitted to the trough 15 at normal main pressure through the conduit 20 and penetrates through the pores of the porous member 11 and issues or departs the sharp edge 23 in a very thin, uniform, vertical curtain C. This falling curtain of water C impinges against the relatively hotter wax coated surface W and administers a sudden chilling to this surface to produce the glossy appearance of the sheet material S, The sheet material S is then wound upon a roll R in a conventional manner.

Any tendency for the falling curtain of water C to contract or part interiorly of the distance spanned by the curtain C, i.e., the transverse width of the sheet S and the length of the porous member 11, is prevented by a pair of identical outriggers 24, 24. Each of the outriggers 24, 24 is substantially cylindrical, slender rod having a body portion 25 and an uppermost end 26 offset with respect to the body 25 at an approximate angle of These offset ends 26 of the outriggers 24 are each secured to the ends (unnumbered) of the porous member 11, or alternatively, the outriggers 24 can be secured to the ends of the head or plate 22 of the manifold 16 in any conventional manner. Each of the outriggers 24 lies in a plane which bisects the angle defined by the converging surfaces 13, 14 of the porous member 11 (FIGURE 2), and each is substantially normal to the lower surface 18 of the plate 22.

As the curtain of water C issues from the edge 23 of the porous member 11, the curtain C continually falls in a vertical unbroken pattern along the entire length of the outriggers 24, 24 and contracts laterally or transversely only after the curtain C passes beyond the lowermost extremities of the outriggers 24. Since the outriggers 24, 24 each project beyond the sheet of material S no contraction of the curtain C occurs between the time the water issues from the edge 23 and the time the water strikes the wax coating W. Thus, the resultant falling curtain of water C is extremely stable, extremely uniform in thickness, relatively free of ripples, and is of a substantially lower velocity than curtains created by conventional weir-like structures.

As has been heretofore noted, the elongated porous member 11 is illustratively constructed from porous carbon. However, since it is not always possible to obtain porous carbon in sutficiently long units, a required length can be built up from a series of individual porous carbon members secured in end-to-end relationship, in a manner shown in FIGURE 3 of the drawing. Each of three units 27, 2S and 30 is identical to the apparatus 10 of FIG- URES l and 2 with the outriggers 24, 24 omitted for purpose of simplicity of illustration. Each of the units 27, 28 and 30, is approximately one foot long and an identical gasket 31 is seated between adjacent ones of the units 27, 28 and 30. The gaskets 31 are each preferably constructed from blotting paper, but may also be constructed from metal, rubber or plastic material having a thickness of approximately of an inch. The gaskets 31 insure intimate contact between adjacent units and thus avoid any interruption of the falling water curtain at the abutting ends of the units. This arrangement also has the advantage of permitting the replacement of any one of the three units 27, 28 and 30 in the event one of these units becomes obstructed or clogged.

The gaskets 31 each preferably have a transverse crosssectional configuration identical to the transverse crosssectional configuration of the porous member 11. That is, the gaskets 31 each include converging sides and an upper cutout portion complementing the trough of the porous member 11. Thus, water introduced into each of the units 27, 28 and 30 flows freely between these units. If it is desired to control the amount of water or other liquid issuing from the individual units 27, 28 and 30, the gaskets 31 between these members are not provided with cutouts corresponding to the cross-sectional shape of the trough 15 but are instead constructed to cover the entire triangular end area of the units 27, 28 and 30. In this case, the gaskets 31 are also preferably constructed of metallic or rubber material to prevent the flow of liquid from one of the units into either of the remaining two units. By selectively adjusting the liquid pressure in the individual units 27, 28 and 30 through appropriate valve mechanisms, the portion of the falling curtain of Water issuing from each of these units can be selectively increased or decreased during the chilling operation.

Another apparatus for creating a uniformly thin curtain of falling liquid coolant, such as water is illustrated in FIGURE 4 of the drawing and is generally designated by the reference numeral 40. The apparatus comprises a substantially elongated porous member 41 constructed from porous material, such as porous carbon or sintered metal. The porous member 41 includes an upwardly opening elongated trough 42 of a substantially U-shaped cross-sectional configuration, and a pair of downwardly converging side walls or surfaces 43, 44 terminating abruptly at a relatively sharp elongated edge 45. The converging surfaces 43 and 44 are each outwardly concavely curved at 46- and 47 respectively, adjacent the longitudinal edge 45.

A manifold 48 comprising a plate or head 49 and a conduit 50 is bonded or otherwise conventionally secured to an upper surface 51 of the porous member 41. The manifold 48 is identical to the manifold 16 of FIGURES 1 and 2 of the drawing, and is adapted for connection to a conventional source of pressurized liquid coolant. If desired, a seal such as the seal 17 of FIGURE 2 may be positioned between the plate 49 of the manifold 48 and the porous member 41, and the porous member 41 may be provided with outriggers at opposite end portions thereof, such as the outriggers 24, 24 of FIGURE 1.

Another apparatus 52 (FIGURE 5) for creating a uniformly thin curtain of falling water or liquid comprises a substantially elongated porous member 53 constructed from porous carbon or sintered metal. The porous member 53 includes an elongated trough 54 of a substantially U-shaped configuration opening upwardly, outwardly through an upper surface 54 of the member 53. Elongated side walls or surfaces 56, 57 of the porous member 53 converge downwardly and terminate at an elongated edge portion 58. The converging surfaces 56 and 57 of the porous member 53 are each outwardly convexly curved at 59 and 60 respectively adjacent the elongated edge portion 58. An elongated impervious element 61 extends the entire longitudinal length of the porous member 53. The impervious member 61 is preferably constructed from metallic material, and is either adhesively bonded in a groove (unnumbered) formed in the edge portion 58 of the porous member 53 or the material forming the porous member 53 is molded to the element 61 during the manufacture of the porous member 53.

A manifold 62 having a head or plate 63 and a conduit 64 is secured to the upper surface 55 of the porous member 53 in a manner heretofore described. The conduit 64 places the trough 54 of the porous member 53 in liquid communication with a pressurized source of coolant material, such as water, in a manner heretofore described in the consideration of FIGURES 1 and 2 of the drawing. If desired or found necessary, the apparatus 52 may also be provided with a seal between the head 63 and the porous member 53.

Another apparatus for creating a uniformly thin curtain of falling liquid in accordance with this invention is illustrated in FIGURES 6 and 7 of the drawing, and is generally designated by the reference numeral 65. The apparatus 65 comprises a pair of elongated, downwardly converging, impervious members 66 and 67. Edges 68 and 69 of the respective impervious members 66 and 67 define therebetween a generally elongated narrow gap or slot (unnumbered). An expandable element, which is preferably a conductive element or wire 70 is helically wound about the impervious member 66 of the apparatus 65. The wire '70 is connected to a source of electric potential 71 in a conventional manner, and as the wire 70 is heated it will expand to increase or vary the width of the elongated slot (unnumbered) between the walls 68 and 69. In this manner, water or other coolant introduced between the members 66 and 67 will flow through the elongated gap to form a thin curtain of falling fluid, and the thickness of this curtain can be varied by increasing or decreasing the potential output of the source 71.

The wire 70 is illustrated being helically wound around the elongated member 66 but this wire 70 may also be wound only around the member 67, or wound alternatively around both of the members 66 and 67. In addition, end plates (not shown) are preferably secure between the transverse edges (unnumbered) of the members 66 and 67 to prevent water introduced between the members 66 and 67 from flowing laterally beyond these members. A manifold, such as any one of the manifolds 16, 48 and 62 can be secured between the uppermost longitudinal edges of the members 66 and 67 to introduce fluid into the volume defined by the members 66, 67 and the end walls (not shown) secured between adjacent transverse edges of these members.

The apparatus heretofore described are each used for the primary function of creating a thin curtain of coolant such as water or other suitable liquids, and directing this curtain of water against a surface of a moving sheet of material. However, it will be readily recognized that the porous members 11, 41, 53 andthe impervious member or apparatus 65 can be employed for applying other liquid mediums such as lacquers, solvents or plastics directly to the surface of a web of material passing beneath these members. In this case, the manifolds are connected to a pressurized source of coating liquid, as opposed to a source of liquid coolant, and the coating liquid is forced to issue from the members in a generally uniformly thin curtain of falling coating liquid. Thus, apparatuses of FIGURES 1 through 7 can not only create a curtain of cooling liquid when employed in the manner immediately above-described, but can also form a curtain of coating liquid in the case of solvents or lacquers, and a thin cur-. tain or film in the case of plastics, in a manner to be described hereafter. Furthermore, the apparatus 65 of FIG- URES 6 and 7 can also heat the coating liquid prior to the formation of the curtain. In the case of relatively viscous coating materials and plastics, such heating is desirable and oftentimes necessary.

It should also be particularly noted that the porous members 11, 41 and 53 can be similarly heated to heat viscous liquid Within the respective troughs 15, 42 and 54 prior to the formation of the falling coating curtain. To this end the porous carbon or sintered metal members 11, 41 and 53 can themselves be made part of an electrical circuit energized by a source of potential energy, in the manner considered during the description of the apparatus 65. However, in this case, the need for an expandable element, such as the wire 70 is not necessary and the porous members themselves form the resistance element of the electrical circuit. This heating of the porous members lowers the viscosity of the coating liquids including plastics, and permits local and immediate control of a coating process employing any one of the members 11, 41 or 53.

As an alternative, the porous members 11, 41 and 53 can be drilled longitudinally and heating wires inserted therein.

During many conventional processes, it is necessary to form an aerated film by the mixing of a gaseous medium and a liquid, and depositing such an aerated film upon a moving surface, in much the same manner as the curtain C of FIGURE 1, is applied against the wax coating W of the sheet 5. An apparatus 75 of FIGURE 8 is constructcd primarily for the purpose of creating an aerated film or curtain and depositing such an aerated curtain onto a moving sheet or web of material.

The apparatus 75 is similar to the apparatus of FIG- URE 4, and comprises an elongated porous member 76 which is preferably constructed from porous carbon or sintered metallic material. The porous member 76 has a top surface 77 and a pair of downwardly converging walls or surfaces 78 and 79. Each of the converging surfaces 78 and 79 are outwardly concavely curved at 80 and 81 respectively, and terminate at a relatively sharp, elongated edge 82 which extends the entire length of the porous member 76. A shallow U-shaped trough 83 opens upwardly through the surface 77 of the porous member 76.

A manifold 84 substantially identical to the manifold 16 of FIGURES 1 and 2, is secured to the surface 77 of the porous member 76. A conduit 85 is threaded into an opening (unnumbered) formed on a plate or head 86 of the manifold 84. The conduit 85 places the trough 83 in fluid communication with a source of compressed air or other such gaseous medium. If found necessary or desirable, a suitable seal, such as the seal 17 of FIGURE 2, may be inserted between the plate 86 and the porous member 76 of the apparatus 75.

Gates 87 and 88 are supported in a conventional manner adjacent the respective converging surfaces 78 and 79 of the porous member 76. The gates 87 and 88 are substantially as long as the porous member 76, and are preferably closed at opposite ends thereof by an identical end wall 89 (only one of which is illustrated). The gates 87 and 88 terminate in respective lower longitudinal edges 90 and 91 which are spaced slightly from the converging surfaces 78 and 79 respectively of the porous member 76 to establish a narrow gap or slot (unnumbered) which runs the substantial entire length of the porous member 76.

Liquid L flows along the converging surfaces 78 and 79 of the porous member 76 after passing beyond the lower longitudinal edges 90 and 91 of the respective gates 87 and 88. This liquid L adheres by capillary action to the converging surfaces 78 and 79 and flows downwardly toward the edge 82. At the same time, compressed air introduced into the trough 83 is forced through the numerous pores of the porous member 76 and issues outwardly therefrom along the elongated edge 82. As the air departs from the elongated edge 82, it mixes with the liquid L flowing down the converging surfaces 78 and 79 of the porous member 76 to create a uniformly thin curtain of aerated fluid F. This aerated curtain of fluid F is, of course, deposited upon an exposed surface of a moving web or sheet in a manner substantially identical to that heretofore described with respect to FIGURES 1 and 2 of the drawing. In addition, the porous member 76 of the apparatus 75 can be provided with Outriggers such as 24, 24 to prevent contraction of the fluid curtain F, and the porous member 76 can be heated in substantially the same manner as the porous members 11, 41 and 53, are heated to permit relatively free flow of the liquid L, when this liquid is of a relatively viscous nature. It should also be particularly noted that the porous member 76 also performs the dual function of adjusting the width of the elongated gap or slot between the gates 87 and 88 and the converging surfaces 78, 79 respectively when the porous member 76 itself forms a resistance element in an electrical circuit. That is, the porous member '76 will expand when heated to not only heat the liquid L, but also reduce the width of the elongated gaps to reduce the flow of the liquid L along the converging surfaces 78 and 79.

Referring to FIGURE 9 of the drawing, an apparatus 95 for creating a uniformly thin curtain of falling aerated fluid comprises a first elongated porous member 96 and a second porous elongated member 97. Both of the porous members 96 and 97 are preferably constructed from porous carbon or sintered metallic material. However the porosity of the first member 96 is substantially greater than the porosity of the second member 97.

The first porous member 96 is substantially triangularly shaped in transverse section and includes a top wall 98, converging side walls 100, 101 and a relatively sharp, elongated lowermost edge 102.

The porous member 97 is divided symmetrically along substantially the entire longitudinal length thereof, and each symmetrical portion of the porous member 97 includes a top surface 103, an internal wall 104 which is substantially normal to the top surface 103, an inclined inner wall or surface 105 and an inclined outer wall or surface 106. Each of the walls or surfaces 105, 106 of the porous member 97 and the walls or surfaces 100 and 101 of the porous member 96 converge generally downwardly toward the elongated edge 102, as is clearly illustrated in FIGURE 9 of the drawings. The inclined inner and outer walls and 106 respectively of the porous member 97 also terminate adjacent the elongated edge 102 of the porous member 96. The outer surface or walls 106, as well as the minute gap at the area of contact between these surfaces and the edges 100 and 101 of the porous member 96 are preferably sealed to prevent the loss of gas outwardly of the porous member 96 during the operation thereof as will appear more apparent hereafter.

The porous member 96 is positioned between the inner inclined walls 105, 105 of the porous member 97 and the top surface 98 of the porous member 96 is positioned substantially at the junction of the walls 104 and 105 of the porous member 97. In this manner, the top surface or wall 98 of the porous member 96 and the walls 104, 104 of the porous member 97 set off an upwardly opening, substantially U-shaped trough 107. A downwardly opening substantially U-shaped manifold 108 having an elongated plate 110 and integral depending, spaced legs 111, 111 is seated in the trough 107. The manifold 108 is preferably immovably secured in the trough 107 by an adhesive bond between the legs 111, 111 and the walls 104, 104 of the porous member 97. A conduit 112 opens through the plate 110 of the manifold 108 and places the trough 107 in liquid communication with a conventional source of liquid supply, which may, for example be a pressurized source of liquid lacquer or solvent.

A manifold 113 of a substantially inverted U-shaped configuration overlies the manifold 108. The manifold 113 includes a substantially elongated plate or head 114 and a pair of depending, identical legs 115, 115. The lowermost edges of the legs 115, 115 are preferably adhesively secured to the upper surfaces 103 of the porous member 97. The interior of the manifold 113 and the upper surfaces 103, 103 of the porous member 97 cooperate to define a trough 109 which is placed in fluid communication with a source of pressurized air or other gaseous medium by a conduit 116 secured to an opening (unnumbered) of the plate 114. The conduit 116 is preferably, but not necessarily, coaxial with the conduit 112. As air is simultaneously introduced into the manifold 113 through the conduit 116 and liquid is introduced into the trough 187 through the conduit 112, these fluids are forced through the respective porous members 97 and 96 toward the elongated edge 102 of the porous member 96. As these tfluids flow beyond the top surface 98 of the first porous member 96, they begin to admix during the remainder of their travel through the porous members 96 and 97 until such time as the admixed fluids issue from the elongated edge 102 of the porous member 96 in a substantially uniform and thin curtain of aerated fluid. This curtain of aerated fluid, can as in the case of the apparatus 75, be employed to administer a substantially uniform coating of fluid to a web or sheet of material passing below and beyond the apparatus 95.

It should also be particularly noted that the porous member 96, the porous member 97 or both of these porous members can be provided with outriggers, such as the outriggers 24, 24 of FIGURE 1, and either or both of the porous members 96 and 97 can form the resistance element in an electrical circuit in the manner heretofore described. Either or both of the porous members 96 and 97 may also be longitudinally drilled for the reception therein of heating wires.

Another apparatus for creating a uniformly thin curtain of falling aerated fluid is shown in FIGURE of the drawings, and is generally designated by the reference numeral 120. The apparatus 120 comprises a porous member 121 which is elongated, and is preferably constructed from porous carbon, porous ceramic, porous plastic or sintered metal. The porous member 121 is substantially triangularly shaped in transverse section and includes a top wall or surface 122, converging side walls or surfaces 123, 124 and a relatively sharp, elongated lowermost edge portion 125 terminating in an elongated sharp edge 126.

A downwardly opening substantially U-shaped manifold 127 having an elongated plate or head 128 and integral depending spaced legs 130, 130 is adhesively bonded to the upper surface 124 of the porous member 121. The manifold 127 is preferably immovably secured to the upper or top surface of the porous member 121 by an adhesive bond between the legs 130, 130 and the top wall 122. A conduit 131 opens through the plate 128 of the manifold 127 and places a trough or chamber 132 in liquid communication with a conventional source of liquid supply, which may, for example, be a pressurized source of liquid lacquer or solvent.

A second manifold 133 is of a two-piece construction and comprises identical downwardly converging legs 134, 134 and upper plates or heads 135, 135. The plates or heads 135, 135 define therebetween a groove or slot (unnumbered) in which is received the manifold 127. The heads 135, 135, are welded or otherwise conventionally secured to opposite longitudinal edges of the plate 128 of the manifold 127. The lowermost edges of the legs 134, 134 are preferably adhesively secured to the surfaces 123 and 124 of the elongated porous member 121. The interior of each side of the manifold 133 is placed in fluid communication with a source of pressurized air or other gaseous medium by an identical conduit 136, 136 secured adjacent an opening (unnumbered) in each of the plates 135, 135.

As air is simultaneously introduced into the manifold 133 through the conduit 136, 136 and liquid is introduced into the manifold 127 through the conduit 131, these fluids are forced through the walls 123, 124 and 122 respectively, toward the elongated edge portion 125 of the porous member 121. As these fluids flow through the porous member 121, they begin to admix during the travel therethrough until such time as the admixed fluids issue from the elongated edge 126 in a substantially uniform and thin curtain of aerated fluid. This curtain of aerated 10 fluid can, as in the case of the apparatuses heretofore described, be employed to administer a substantially uniform coating of aerated fluid to a web or sheet of material passing below and beyond the apparatus The porous member 121 can also be provided with outriggers (not shown) such as the outriggers 24, 24 of FIG- URE 1, and the porous member 121 can also form the resistance element in an electrical circuit in the manner heretofore described. The porous member 121 can also be longitudinally drilled for the reception therein of heating wires, particularly when the apparatus 120 is employed to form an aerated curtain or film of plastic material, as will be described hereafter.

Referring to FIGURE 11 of the drawings, an apparatus 140 for creating a uniformly thin curtain of falling aerated fluid comprises a first elongated porous member 141 and a pair of identical second porous elongated members 142, 142. Each of the porous members 141, 142 and 142 are preferably constructed from porous carbon, porous ceramic or sintered metallic material. However, the porosity of the porous member 141 is substantially greater than the porosity of either of the porous members 142, 142.

The porous member 141 is substantially triangularly shaped in transverse section and includes a top Wall or surface 143, identical converging side walls or surfaces 144, 145, a lowermost edge portion 146 and a relatively sharp, elongated lowermost edge 147.

Each of the porous members 142 includes a top surface 148, an innermost inclined Wall or surface 150 and an outermost inclined wall or surface 151. Each of the walls or surfaces 144, 145, 150 and 151 converge generally downwardly toward the elongated edge 147, and a lowermost edge (unnumbered) of each of the porous members 142, 142 terminates substantially midway between the edge 147 and the top surface 143 of the porous member 141.

A downwardly opening substantially U-shaped manifold 152 having an elongated plate or head 153 and integral, identical, depending spaced legs 154, 154 is seated on the top wall 143 of the porous member 141. The manifold 152 is preferably immovably secured to the porous member 141 by adhesively bonding the legs 154, 154 to the wall 143 of the porous member 141. A conduit 155 opens through the plate 153 of the manifold 152 and places the interior thereof in fluid communication with a conventional source of liquid supply, such as pressurized liquid lacquer, solvent or plastic material.

A manifold 156 of a twopiece construction includes a substantially elongated plate or head 157 and a pair of depending, converging identical legs 158, 158. The lowermost edges (unnumbered) of the legs 158, 158 are preferably adhesi-vely secured to the outer walls or surfaces 151, 151 of each of the porous members 142, 142. The interior (unnumbered) of the manifold 156 is placed in fluid communication with a source of pressurized air or other gaseous medium by an identical conduit 160 on each side of the conduit 155.

The operation of the apparatus 140 is substantially identical to the operation of the apparatus of FIGURE 9, and a further description thereof is deemed unnecessary for a complete understanding of this invention. However, it should be particularly noted that the curtain of fluid formed by the apparatus 140 is of an aerated nature.

An apparatus constructed in accordance with this invention for creating a uniformly thin tubular curtain of falling fluid is best illustrated in FIGURES 12 and 13 of the drawings, and is generally designated by the reference numeral 165.

The apparatus comprises a substantially circular porous member 166 (FIGURE 13), of a generally triangular cross-sectional configuration having a top wall or surface 167 and two downwardly, converging walls or surfaces 168 and 170. The porous member 166 is illustratively constructed from porous carbon, but may also be constructed from porous ceramic, sintered metal or porous plastic material. A trough 169 of a substantially shallow U-shaped configuration opens upwardly to the surface 167 of the porous member 166, and extends substantially the entire circumference of the circular porous member 166.

A circular fluid manifold 171 is bonded or otherwise conventionally secured to the upper surface 167 of the circular porous member 166. If desired, a seal or gasket such as the seal or gasket 17 of FIGURE 2, can be seated between the upper surface 167 of the porous member 166 and a lowermost surface 172 of the manifold 171 to prevent the leakage of fluid in a known manner. A conduit 173 having a threaded end portion 174 is secured in a threaded opening 175 of the manifold 171. The conduit 173 is placed in liquid communication with a source of pressurized fluid or plasticized plastic material, such as polyethylene, by connecting the conduit 173 to a conventional extrusion machine.

Both the conduit 173 and the manifold 171 are preferably coated with an insulating layer of material (not shown) to maintain the plastic material in a fluid state. If desired, or found necessary, the porous member 166 of the apparatus 155 can also be heated by means of a resistant element or by the porous member 166 itself forming a resistance element of an electrical circuit in a manner heretofore described.

The apparatus 165 is supported substantially in parallel relationship to the horizontal, as is best shown in FIGURE 12, and a generally continuous tubular member T is conveyed downwardly through an opening (unnumbered) defined by the apparatus 165. The tube T can be, for example, a continuously longitudinally seamed or spirally wound tube constructed from paper or other flexible material from which can bodies are formed by severing the tube T in a known manner into discrete lengths.

Plasticized plastic material, such as polyethylene, is admitted through the conduit 173 of the apparatus 165 and penetrates through the pores of the porous member 166 and issues or departs from a relatively sharp circular edge 176 in a very thin, uniform circular or tubular curtain C of plastic material. The surface tension of the plastic material causes the generally cylindrical falling film C to assume a generally conical shape between the edge 176 of the porous member 166 and an exterior surface (unnumbered) of the tube T. This plastic curtain or film C adheres to and uniformly coats the exterior surface of the tube T, in a manner clearly illustrated in FIGURE 12 of the drawings.

The apparatus 165 is, as has been heretofore noted, preferably constructed from a one-piece circular porous member 166 and a one-piece manifold 171. However, the apparatus 165 may also be built up from a series of individual curved porous members and manifold sections in much the manner as is shown in FIGURE 3 of the drawings.

While the apparatus 165 has been illustratively described to form a curtain or film or plastic material, it is to be understood that the apparatus 65 can also be connected to a suitable source of pressurized coolant for introducing a substantially uniform, thin, uninterrupted curtain of coolant against a surface of a tubular member. Such a tubular member could, for example, be wax coated in much the manner as the sheet S of FIGURE 1 and the coolant or water introduced against the hotter wax coated exterior surface of the tube T would chill the same and form a glossy external appearance at the exterior of the tube T.

Each of the apparatuses of FIGURES 1 through 13 of the drawings has been described in conjunction with either cooling or coating a continuous web or tube by creating a falling planar or tubular curtain. However, each of the FIGURES 1 through 13 disclosures of the invention are also capable of being used to form a continuous sneer or tube of homogeneous or aerated plastic material.

12 To this end, attention is now particularly directed to FIGURE 14 of the drawings which illustrates an apparatus suitably supported in a conventional manner above a conveyor mechanism 181.

The apparatus 180 can be any one of the apparatuses of FIGURES 1 through 11 of the drawings, and comprises an elongated porous member 183, a manifold 184, a pair of identical outriggers 185, and a conduit 186. The conduit 186 is particularly adapted to be connected to a conventional extrusion machine or extruder.

The conveyor or conveyor mechanism 181 comprises an endless belt conveyor 187 having an upper conveyor belt run 188 and a lower conveyor belt run 190. The conveyor belt 187 is entrained about a roller 191 and an idler chill roll 192. The idler chill roll 192 is of a hollow construction and has opposite identical conventional rotatable unions 193 and 194. The union 193 is placed in fluid communication with a suitable supply of coolant material, such as water, by a conduit 195.

The union 194 is similarly placed in fluid communication with a fluid reservoir by means of a conduit 196.

A stripper or blade 197 having an edge 198 may be positioned beneath and traverses the lower conveyor belt run and the conveyor 181. The blade 197 is directed toward the idler chill roll 192, and cooperates in a conventional manner with a winding or rewind roll 200 of a conventional rewind mechanism.

Plastic material is introduced into the apparatus 180 from a conventional extruder through the conduit 186 and this plastic material penetrates through the pores of the porous member 183 and departs or issues from the shar edge (unnumbered) of the porous member 183 in a very thin, uniform planar vertical curtain or film P of plastic material, such as polyethylene. This falling curtain or film of plastic material impinges against the upper surface of the upper conveyor belt run 188 of the conveyor mechanism 181. The plastic film P progressively and uniformly coats the upper surface of the upper conveyor run 188 as this conveyor run is moved from left-to-right as viewed in FIGURE 14 by driving any one or all of the rolls 191, 192 or 200 by a conventional driving mechanism (not shown) to form a continuous sheet S of plastic material. As the plastic sheet 5 is conveyed by the conveyor belt 187 about a portion of the periphery (unnumbered) of the idler chill roll 192, the sheet S of plastic material is cooled and set. Thereafter, the edge 198 of the blade 197 aids in peeling or removing the now chilled plastic sheet S from the lower run 190 of the conveyor 181 after which the plastic sheet is then wound in a conventional manner on the roll 200 of the rewind mechanism (unnumbered). The entire external surface of the conveyor belt 187 upon which the film P impinges is preferably coated with carbon tetrafluoroethylene which aids in the removal of the plastic sheet of film S from the lower conveyor run 190 by the blade 197.

The apparatus 165 of FIGURES 12 and 13 has already been described as forming a continuous tube C of plastic material, such as polyethylene, which is applied to an exterior surface of the continuous tube T passing through the opening (unnumbered) in the apparatus 165. However, by merely transporting the continuous tube or film C of plastic material through a conventional internal or external cooling coil or sleeve (not shown) supported immediately below and in axial alignment with the apparatus 165, the tube or tubular film C of plastic material will be chilled and set upon leaving the edge 176 of the porous member 166. Thereafter, this continuous tube or film C can be wound upon a rewind roll of a conventional rewind mechanism in the manner heretofore described, thereby forming a continuous tube or tubular film of either aerated or homogeneous plastic material.

Various modifications of the disclosed invention will be apparent to those skilled in the art after reviewing this disclosure, and such modifications are considered to be within the scope and spirit of this invention. For example, the seal or gasket 17 between the porous member 11 and head 22 of FIGURE 2 can not only be constructed from material which prevents escape of fluid, but may also be constructed from insulating material to prevent heat or electrical conduction from the porous member 11 to the manifold 16 when the porous member 11 forms the resistance element in an electric circuit.

A seal, such as the seal 17, may also be incorporated in each of the apparatuses 48, 52, 75, 95, 120 and 140, and such seal can be constructed of insulated material.

In the apparatus 52 of FIGURE 5, the elongated insert or edge 61 can be eliminated and replaced by a plurality of relatively short fibrous whiskers of a metallic or nonmetallic construction. Such whiskers would preferably have an exposed length of approximately one inch and are spaced along the edge portion 58 of the porous member 53 at one inch intervals. These whiskers are preferably constructed from flexible material and would serve to stabilize the fluid curtain at relatively low flow rates, and would additionally aid in preventing contraction of the curtain so formed at these lower rates of flow. Such whiskers, as well as the elongated non-porous insert 61, are not limited to the apparatus 52 of FIGURE 5, but may also be incorporated in the apparatuses of FIGURES 1 through 4, and 8 through 14 of the drawings.

Each of the apparatuses disclosed in FIGURES 4, 5 and 8 through 14 of the drawing can also be divided into individual units, such as the units 27, 28 and 30 of FIG- URE 3, to provide divided operating zones for selectively varying the thickness and rate of flow of a fluid curtain, and if desired, permit utilization of the units so as not to necessitate the formation of a fluid curtain along the entire length of the units. That is, if it is desirable or necessary to coat only selected portions of a moving web of material or to chill only certain portions of a sheet of material which is completely coated with wax, a unit, such as the unit of FIGURE 3, can be employed in an obvious manner to prevent the flow of fluid into any one or selected numbers of the units 27, 28 and 30. In this manner, selected longitudinal portions of a moving web or tube can be selectively chilled or selectively coated.

It is also considered Within the scope of this invention to provide for the application of longitudinal compression forces to the units 27, 28 and 30 of FIGURE 3 to insure sealing contact between adjacent ones of these units in order to avoid an interruption in the fluid curtain at the joints thereof. This may be accomplished by longitudinally boring each of the units 27, 28 and 30 to form one or a plurality of axially aligned bores for receiving one or a plurality of tie rods having nut-receiving threaded end portions projecting beyond exposed end portions of the units 28 and 30.

It is also within the scope of this invention to seal the exposed end portions of each of the porous members with suitable gasket means to prevent longitudinal flow of fluid beyond the troughs associated with the respective porous members.

Any one of the apparatuses disclosed in FIGURES 1 through 14 of the drawings may also be constructed in other than a generally elongated or circular configurations. For example, the circular porous member of FIG- URES 12 and 13 can be constructed in either oval, square or almost any other configurations when a curtain of liquid is directed against structures which complements these latter configurations.

While example disclosures of apparatus for producing uniformly thin curtains of aerated or non-aerated fluid have been disclosed herebefore, it is to be understood that other changes in the disclosed structures and arrangements than those outlined above may be made without departing from the spirit and scope of this invention as defined in the appended claims.

We claim:

1. Apparatus for creating a uniformly thin curtain of liquid comprising a substantially elongated porous memher having substantial width and depth and converging side surfaces terminating at a substantially elongated terminal edge portion, and means for delivering liquid to and through said member whereby the liquid flows toward said elongated edge portion and departs therefrom in a relatively thin and uniform falling curtain of liquid.

2. The apparatus as defined in claim 1 wherein said porous member is constructed from electrically conductive material.

3. The apparatus as defined in claim 1 wherein said porous member is constructed from electrically resistive material.

4. The apparatus as defined in claim 1 wherein said porous member is constructed from non-conductive material and electrically conductive means is carried by said porous member for heating the liquid during its passage through said porous member.

5. The apparatus as defined in claim 1 wherein said porous member is defined by two distinct porous bodies, said delivering means include first manifold means for delivering liquid to and through one of said bodies and the elongated edge portion associated therewith, and additional manifold means for delivering fluid to and through the other of said porous bodies.

6. The apparatus as defined in claim 1 wherein the converging side surfaces are each inwardly concavely curved adjacent the elongated terminal edge portion.

7. The apparatus as defined in claim 1 wherein the converging side surfaces are each inwardly convexly curved adjacent the elongated terminal edge portion.

8. The apparatus as defined in claim 1 including a plurality of spaced slender members project beyond said elongated terminal edge portion.

9. The apparatus as defined in claim 1 wherein the porous elongated terminal edge portion terminates in an impervious elongated edge.

10. The apparatus as defined in claim 7 wherein the porous elongated edge portion terminates in an impervious elongated edge.

11. The apparatus as defined in claim 1 including means for preventing contraction of the falling curtain of liquid.

12. The apparatus as defined in claim 11 wherein said means for preventing contraction comprise at least two members spaced along and projecting substantially beyond said elongated edge portion.

13. The apparatus as defined in claim 4 wherein said electrical conductive means is a heating element positioned partially within said porous means.

14. An apparatus for creating a uniformly thin curtain of liquid comprising first and second porous means, one of said porous means comprising a porous member having an edge, means for delivering fluid to the porous means whereby the same is discharged from the elongated edge to create a uniform falling curtain of liquid, and said first porous means has a greater porosity than the second porous means.

15. The apparatus as defined in claim 14 wherein said delivery means includes a fluid manifold in fluid communication with the first porous means and a gas manifold in fluid communication with the second porous means.

16. Apparatus for creating a uniformly thin curtain of liquid comprising first and second elongated members defining therebetween an elongated gap and expandable means seated in said elongated gap whereby the gap can be adjusted by energizing the expandable means from a source of electric potential.

17. The apparatus as defined in claim 16 wherein the expandable means is an electrically conductive element partially encircling one of the elongated members.

18. The apparatus as defined in claim 16 wherein the expandable means is an electrically conductive element.

19. Apparatus for creating a uniformly thin curtain of falling liquid comprising a plurality of elongated porous 15 means joined in end-to-end relation, gasket means between adjacent ones of the plurality of porous means, and means placing said porous means in longitudinal compression.

20. Apparatus for creating a uniformly thin curtain of liquid comprising a substantially elongated porous member having substantial width and depth and converging side surfaces terminating at a substantially elongated terminal edge portion, means for delivering fiuicl to and through said member, and means for delivering liquid against the exteriors of the converging side surfaces whereby the combined liquid and fiuid departs from the edge portion in a relatively thin and uniform falling curtain.

21. A method of creating a uniformly thin curtain of falling liquid comprising the steps of forcing liquid through a longitudinally extending portion of a porous body having substantial width and depth and converging side surfaces terminating at a substantially elongated terminal edge portion, and forcing gas through contiguous portions of the porous member toward said edge portion whereby both fiuids are directed toward the edge portion and depart therefrom in a relatively thin and uniform falling curtain of liquid.

22. The method as defined in claim 21 including the step of directing the falling curtain in a generally tubular configuration.

23. The method as defined in claim 22 wherein the falling curtain is directed in a generally vertical direction, feeding an article in generally coaxial relationship to the tubular curtain, and forcing the liquid curtain into contact with the article whereby the latter is coated by the falling curtain of liquid.

24. A method of creating a uniformly thin curtain of falling liquid comprising the steps of forcing gas through a longitudinally extending portion of an elongated porous member having substantial width and depth and converging side surfaces terminating at a substantially elongated terminal edge portion, and directing liquid against the exteriors of the side surfaces and toward the terminal edge portion whereby both of the fluids are directed toward the edge portion and depart therefrom in a relatively thin and uniform falling curtain of liquid.

References Cited UNITED STATES PATENTS 2,314,453 3/1943 Mack et al 117-105.3 X 2,579,815 12/1951 Gialanella 264-176 X 2,607,954 8/1952 Schneider et al 264l76 2,987,767 6/1961 Berry et al 18-14 X 3,219,012 11/1965 Stream 118-324 FOREIGN PATENTS 536,641 2/1957 Canada.

1,202,421 7/ 1959 France.

97,789 4/ 1961 Netherlands.

OTHER REFERENCES Toensmeier, Paperboard Packaging," October 1960, pp. B13-B14.

ALFRED L. LEAVITT, Primary Examiner.

J. H. NEWSOME, Assistant Examiner. 

